Well, I'll be. Never would have guessed. First fan-character to make it into the series?
I suppose it makes sense. They've sort of exhausted use of most of the underground cast in the purchasable comics "Calling on Chireiden" and "The Freewheeling Visitor", and the ones that they didn't are mostly with Kogasa right now. I think the only underutilized characters left are Yamame and Okuu, neither of which is suited to be an antagonist in this series.
Also: +1 on the "aww" count for Byakuren being such an anchor and source of comfort in Kyouko's life that she's even serving the role in dreams.